Rotor for use in impact crushers

ABSTRACT

A rotor has a rotor shaft composed of two discrete shaft sections the adjacent ends of which are connected by a sleeve guided in appropriate bores of the ends, so that the shaft sections are axially aligned but have freedom of limited axial relative displacement. Each shaft section carries a rotor end plate fixed to it and extending transversely of it, and a circumferential wall extends between and connects the end plates, surrounding the shaft. Another embodiment is also disclosed.

Unit ed States Patent 11 1 v Smits 1111 3,779,470 1451 Dec. 18, 1973 I 1 ROTORFORUSEINIMPACTCRUSIIERS '[75] Inventor: Barnhard Johannes Smits, Ahaus,

Germany [73] Assignee: Die Hazemag I-Iartzerkleinerungs und Zement-Maschinenbau Gesellschaft m.b.I-I., Muenster, Germany [22] Filed: Sept. 13,1972

211 Appl. No.2 288,792 I [30] Foreign Application Priority Data Sept. 14, 1971 Germany P 21 45 868.4

[52 us. c1. 241/191, 241/293 5 51 1111.0.

[ 56 1 References Cited v UNITED STATES PATENTS 1,774,464 8/1930 Wood 241/67 x B02c 13/28 [58] Field of Search....,...

2,208,316 7/1940 Baxter 241/293 FOREIGN PATENTS OR APPLICATIONS 472,241 2/1929 Germany 241/191 611,867 4/1935 Germany 241/293 Primary ExaminerGranville Y. Custer, Jr. Att0rneyMichael S. Striker [5 7] ABSTRACT A rotor has a rotor shaft composed of two discrete shaft sections the adjacent ends of which are connected by a sleeve guided in appropriate bores of the ends, so that the shaft sections are axially aligned but have freedom of limited axial relative displacement. Each shaft section carries a rotor end plate fixed to it and extending transversely of it, and a circumferential wall extends betweenand connects the end plates, surrounding the shaft.- Another embodiment is also disclosed.

5 Claims, 2 Drawing Figures f ROTOR FOR USE IN IMPACT'CRUSHERS BACKGROUND OF THE. INVENTION The present invention relates generally to armor, and more particularly to a rotor for use in impact crushers. Still more particularly the present invention relates to a rotor for use in impact crushers of the type in which hot air streams are circulated.

Impact crushers of the type mentioned above are sometimes called crusher driers, and their purpose is to comminute material by impact in an impacting chamber and at the same time to effect drying of the material. The drying is effected by the circulation of streams of hot air in the crusher. The comminution by impacting in this type of crusher is effected by a rotor which is mounted in the impact chamber for rotation and upon which the material to be comminuted impinges. Such rotors generally have a continuous rotor shaft provided with two axially spaced rotor end plates which are fixedly secured with the shaft for rotation, and with an inner and/or outer circumferential wall which surrounds the shaft intermediate the end plates and extends between the latter, being fixedly connected with .the end plates. The rotor is further provided with impact or beating instrumentalities which are either mounted in slots provided for this purpose on the outer drum .wall or circumferential rotor wall, or if the rotor wall is located inwardly of the rotor periphcry, in slots which are provided in annular plates mounted on and surrounding the rotor wall.

Evidently, in impact crushers of the type here in question, the rotor is subjected to the influence of the hot air streams circulating in the crusher. This means that in operation the circumferential wall of the rotor becomes very hot, because of its direct and immediate contact with the circulating hot air or other gases. The shaft, however, "is protected to a certain extent by the circumferential wall and the bearing cooling system, and thus-does not become heated'to'anywhere near the extent to which the circumferential wall becomes heated. This means that the shaft and the circumferential wall are subject to different extents of thermalexpansion and contraction, and this in turn results in the development of very significant stresses in the rotor which may lead to deformations and/or cracks.

The'problem has been recognized before and the prior art has attempted to overcome it by securing only of the rotor end plates to the rotor shaft and to mount the other end plate axially displaceable on the rotor shaft. However, experience: has shown that this is not a satisfactory solution, because the rotor is subjected in operation to extremely strong and frequent impacts by the impacting material to be comminuted, so that the mounting of the end plates in such a construction will very rapidly become defective. This, in turn, leads to an imbalance of the rotor which latter then becomes unusable.

It is an object of the present invention to overcome these disadvantages.

More particularly it is an object of the present invention to provide an improved rotor for impact crushers, and in particular for use in impact crushers of the type in which hot gas is circulated in constant contact with the rotor, with the novel rotor avoiding the disadvantages of the prior art. I

The above objects, and others which will become apparent hereafter, are met by a rotor, particularly for use in impact crushers through which hot fluid-streams circulate, which rotor briefly stated comprises a rotor shaft including two discrete shaft sections having respective adjacent ends. Connecting means cooperates with these ends and connects the shaft sections in axially aligned relationship and with freedom of limited relative axial displacement. A pair of axially spaced rotor end plates are provided, each being mounted on one of the shaft sections surrounding and extending transversely of the same and the circumferential wall means extends between and connects the end plates fixedly with one another.

' With this construction, the disadvantages of the prior art are overcome. The development of stresses resulting from differential thermal expansion or contraction of the circumferential wall and the shaft is impossible because the rotor shaft is composed of two discrete shaft sections. On the other hand, the basic strength and stability of the rotor is not weakened because to all intents and purposes the shaft is still a shaft extending all the way through the rotor, a necessity because of the very high weights of the rotor itself and the high impacts to which it is subjected in operation. It is for these reasons, incidentally, that it is not possible to provide each of the end plates with an axially extending stub shaft by means of which the rotor could be journalled, and to omit those shaft portions which extendthrough the rotor from one to the other of the end plates. Such a construction would not be capable of providing the necessary structural strength.

It may be advantageous if the connecting means connecting the ends of the shaft sections, which is advantageously in form of a sleeve or bushing, and/or the ends of the shaft sections, are provided with centering members or spokes which extend in a substantially starshaped arrangement to the circumferential wall means, thus centering the shaft sections on and with reference to'the cirfumferential wall means. This prevents any relative movement of the shaft sections with reference to the circumferential wall means which could'place the axes of the shaft sections skew with reference to the axis of the circumferential wall means. Of course, the spokes or the 'like can be replaced by other suitable centering means, for instance annular plates or the like. In any case, these means serve also to facilitate the assembly of the rotor by centering the shaft sections on insertion into the circumferential wall means. The novel features which are considered as characteristic for the invention are set forth in particular in the ap pended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will best be understood from the following description of specific embodiments when read in connection with J bodiment illustrated inFIG. l, which Figure is an axial section of the rotor, shows a rotor having a circumferential wall 1 and/or la. In other words, the rotor may have the wall 1 and it may additionally have the wall la vor either one of the walls 1 and la may be omitted if desired. In addition, the-wall has two rotor end plates 2 which are welded to the wall 1 and/or 1a at the opposite axial ends thereof and which have connected with them by means of screws 3 the illustrated flanges 4. The flanges 4 are each mounted on one of the two shaft sections 5 and 6 of the rotor shaft, andare welded to the respective shaft section. I

In accordance with the present invention the shaft sections 5 and 6 are axially aligned and have their respective inner ends 7 and 8 adjacent one another. The ends 7 and 8 are connected within the confines of the wall 1 by a sleeve 9 which is placed over them and which serves to maintain them in axial alignment.

The sleeve 9 can be shrink-fitted on the end 8 of the shaft section 6 (or of course of the shaft section 5) or it can be weldedthereto, which is the form of connection illustrated in FIG. 1. A slight axial spacing exists between the ends 7 and 8.

The outer circumferential surface of the sleeve 9 is provided with four spokes 10 which are welded to it in the illustrated embodiment and whose outer edges engage the inner side of the circumferential wall 1, centering the sleeve 9 as well as the shaft section ends 7 and 8 with respect to the wall I. Inlieu of the provision of the spokes 10, or in addition to them, suchspokes can be provided on the shaft sections themselves, at their respective ends.

The rotor is provided in the end plates 2 with radial slots 11 and with one or more annular plates 12 surrounding the wall 1 intermediate the end plates 2. Accommodated in these slots 11 are the beating instrumentalities in form of beating bars or the like of the rotor. They abut rearwardly against supports 13 which connect the plates 2 and 12 within the slots 11 with one another. Of course, the invention is equally applicable to rotors which are constructed in other manner,for instance to rotors having a continuous outer circumferential wall on which holding elements may be welded to which the beating instrumentalities could be secured.

The embodiment illustrated in FIG. 2 differs only in some respects from that of FIG. 1 and like reference numerals have been assigned to like elements. In FIG. 2 the shaft section 6 is provided with a recess in its end 8, thus forming itself a sleeve portion 9 which can be pushed over the end 7 of the shaft section 5, that is which can accommodate the end 7. In this embodiment, as in the other, the shaft sections nevertheless have freedom of limited axial displacement. The beating instrumentalities of the rotor illustrated in FIG. 2

are inserted into non-illustrated slots formed in the circumferential wall la. v

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above. 7

While the invention has been illustrated and described as embodied in a rotor for use in impact crushers in which hot fluid circulates, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention and without omitting features which are essential to the present invention and, therefore such modifications should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be secured by Letters Patent is set forth in the appended claims:

1. A rotor, particularly for use in impact crushers through which hot fluid streams circulate, comprising a rotor shaft including two discrete shaft sections having respective adjacent ends; connecting means cooperating with said ends and connecting said shaft sections in axially aligned relationship and with freedom of limited relative axial displacement; a pair of axially spaced rotor endplates each mounted on one of said shaft sections surrounding and extending transversely of the same; and circumferential wall means extending between and connecting said endplates fixedly with one another.

2. A rotor as defined in claim 1, wherein said connecting means comprises a connecting sleeve.

3. A rotor as defined in claim 2; and further comprising centering members provided on said sleeve and centering the same with reference to said circumferential wall means.

4. A rotor as defined in claim 2; and further comprising centering members provided on said ends for centering the latter with reference to said circumferential wall means.

5. A rotor as defined in claim 2; and further comprising centering members provided on at least one of said sleeve or ends for centering the same with reference to said circumferential wall. 

1. A rotor, particularly for use in impact crushers through which hot fluid streams circulate, comprising a rotor shaft including two discrete shaft sections having respective adjacent ends; connecting means cooperating with said ends and connecting said shaft sections in axially aligned relationship and with freedom of limited relative axial displacement; a pair of axially spaced rotor endplates each mounted on one of said shaft sections surrounding and extending transversely of the same; and circumferential wall means extending between and connecting said endplates fixedly with one another.
 2. A rotor as defined in claim 1, wherEin said connecting means comprises a connecting sleeve.
 3. A rotor as defined in claim 2; and further comprising centering members provided on said sleeve and centering the same with reference to said circumferential wall means.
 4. A rotor as defined in claim 2; and further comprising centering members provided on said ends for centering the latter with reference to said circumferential wall means.
 5. A rotor as defined in claim 2; and further comprising centering members provided on at least one of said sleeve or ends for centering the same with reference to said circumferential wall. 